Parallel optical coherence tomography apparatuses, systems, and related methods

ABSTRACT

Provided is a snapshot spectral domain optical coherence tomographer comprising a light source providing a plurality of beamlets; a beam splitter, splitting the plurality of beamlets into a reference arm and a sample arm; a first optical system that projects the sample arm onto multiple locations of a sample; a second optical system for collection of a plurality of reflected sample beamlets; a third optical system projecting the reference arm to a reflecting surface and receiving a plurality of reflected reference beamlets; a parallel interferometer that provides a plurality of interferograms from each of the plurality of sample beamlets with each of the plurality of reference beamlets; an optical image mapper configured to spatially separate the plurality of interferograms; a spectrometer configured to disperse each of the interferograms into its respective spectral components and project each interferogram in parallel; and a photodetector providing photon quantification.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. application Ser. No.14/266,263, filed Apr. 30, 2014, now U.S. Pat. No. 9,155,465, whichclaims priority from U.S. Provisional Application No. 61/817,413, filedApr. 30, 2013, the benefit of each of which is claimed hereby, and eachof which are incorporated herein in its entirety.

FIELD OF THE INVENTION

The present invention relates to optical coherence tomography imagers.

BACKGROUND OF THE INVENTION

Optical Coherence Tomography (OCT) is a technique to measure depthdependent refractive index changes at a single location, and can be usedfor two- and three-dimensional imaging of tissue and othersemi-transparent materials. 3D OCT is primarily used in the eye, toimage the retina and retinal abnormalities and the cornea and cornealabnormalities at high resolution. The principle of OCT is based uponlow-coherence interferometry, where the backscatter from more outerretinal tissues can be differentiated from that of more inner tissuesbecause it takes longer for the light to reach the sensor. Because thedifferences between the most superficial and the deepest layers in theretina and the cornea are around 100-400 μm, the difference in time ofarrival is very small and requires interferometry to measure. Thespectral-domain OCT (SDOCT) improvement of the traditional time-domainOCT (TDOCT) technique, known also as Fourier domain OCT (FDOCT), makesthis technology suitable for real-time cross-sectional retinal imagingat video rate.

OCT imagers presently on the market are expensive and complex becausethey depend on scanning across the retina, which is typically performedthrough galvanic mirrors that deflect measurement light. Galvanicmirrors require precise adjustment, have finite latency and responsetime, and substantially increase complexity and cost of OCT imagers.Because of this substantial cost and complexity, the availability of OCTimagers is limited and thus many in the population have limited accessto retinal examinations that could be key to the early detection andpreventative treatment of conditions such as diabetic retinopathy. Thereis a need in the art for a low-cost OCT imager that could be cheaply andeasily deployed to locations such as primary care clinics, drug storesand retail stores, or even at home to allow for increased access to highquality retinal scans.

BRIEF SUMMARY OF THE INVENTION

In an aspect, provided is a snapshot spectral domain optical coherencetomographer comprising a light source providing a plurality of beamlets;a beam splitter, splitting the plurality of beamlets into a referencearm and a sample arm; a first optical system that projects the samplearm onto multiple locations of a sample; a second optical system forcollection of a plurality of reflected sample beamlets; a third opticalsystem projecting the reference arm to a reflecting surface andreceiving a plurality of reflected reference beamlets; a parallelinterferometer that provides a plurality of interferograms from each ofthe plurality of sample beamlets with each of the plurality of referencebeamlets; an optical image mapper configured to spatially separate theplurality of interferograms; a spectrometer configured to disperse eachof the interferograms into its respective spectral components andproject the spectral components of each interferogram in parallel; and aphotodetector configured to receive the spectral components of eachinterferogram and provide in parallel photon quantification.

In an aspect, provided is a snapshot spectral domain optical coherencetomographer comprising a housing and a system of optical componentsdisposed in the housing capable of parallel optical coherence imaging ofa sample; a broadband low coherence light source providing light to abeam splitter wherein the beam splitter splits the light into areference arm and a sample arm; a first optical element converting thesample arm into a plurality of beamlets and focusing the plurality ofbeamlets on the sample; a reflecting surface reflecting light from thereference arm, wherein the light reflected from the reflecting surfaceis recombined with the plurality of beamlets reflected from the sampleproducing a plurality of beamlet interferograms; an optical image mapperconfigured to receive and spatially separate the plurality of beamletinterferograms; a spectrometer configured to disperse each of thebeamlet interferograms into its respective spectral components andproject the spectral components of each interferogram in parallel; aphotodetector configured to receive the spectral components of eachbeamlet interferogram and provide in parallel photon quantification; anda computer module wherein said computer module performs inversetransforms on the photon quantifications and quantifies intensities ateach depth.

In an aspects, provided is method of imaging an eye comprising providinga plurality of low coherence beamlets; transmitting the plurality of lowcoherence beamlets to a beam splitter, wherein the beam splitter splitsthe plurality of beamlets into a reference arm directed to a reflectingsurface and a sample arm directed to multiple locations of an eye;recombining beamlets reflected from the reflecting surface and beamletsreflected from the eye generating a plurality of interferograms;converting the plurality of beamlets to a linear array of beamlets;dispersing each of the plurality of beamlets into its spectralcomponents; and performing in parallel photon quantification of each ofthe plurality of beamlets.

In an aspect, the method further comprises performing inverse transformson the photon quantifications and quantifying the intensities at eachdepth of the eye. In certain aspects, the method further comprisesinterpreting the intensities and providing an aggregate response of theeye. In still further aspects, the method further comprises calculatingretinal thickening. In yet further aspects, the method further comprisescalculating nerve fiber layer thinning.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the snapshot OCT apparatus according tocertain embodiments.

FIGS. 2A-B are schematic diagrams of alternative embodiments of thesnapshot OCT apparatus, according to certain embodiments.

FIGS. 3A-C are diagrams of image mapper optical configurations,according to certain embodiments.

FIG. 4A-B are diagrams of the spectrometer, according to certainembodiments.

FIG. 5 is schematic diagram of the spectrometer dispersive device,according to certain embodiments.

FIG. 6 is schematic diagram of the spectrometer dispersive device,according to certain embodiments.

FIG. 7 is an image of the spectrum from point sources from the detectorplane, according to certain embodiments.

FIG. 8 is a diagram of the image mapper optics, according to certainembodiments.

FIG. 9 is a diagram of the image mapper and spectrometer, according tocertain embodiments.

FIG. 10 is a block diagram of the image analysis process according tocertain embodiments.

FIG. 11 is a flow chart of disclosed methods according to certainembodiments.

FIG. 12 shows a block diagram of an exemplary system.

DETAILED DESCRIPTION

The invention now will be described more fully with reference to theaccompanying drawings, in which illustrative embodiments of theinvention are shown. Although the present invention has been describedwith reference to preferred embodiments, persons skilled in the art willrecognize that changes may be made in form and detail without departingfrom the spirit and scope of the invention.

Throughout the description and claims of this specification, the word“comprise” and variations of the word, such as “comprising” and“comprises,” means “including but not limited to,” and is not intendedto exclude, for example, other additives, components, integers or steps.“Exemplary” means “an example of” and is not intended to convey anindication of a preferred or ideal embodiment. “Such as” is not used ina restrictive sense, but for explanatory purposes.

In exemplary embodiments, the apparatus disclosed herein is a snapshotspectral domain optical coherence tomographer comprising a housing and asystem of optical components disposed in the housing capable of paralleloptical coherence imaging of an object. An array of broadbandlow-coherence light sources provides a plurality of beamlets and a beamsplitter positioned to receive the plurality of beamlets splits theplurality of beamlets into a reference arm and a sample arm, with eacharm comprising a plurality of beamlets. A first optical system projectsthe sample arm onto multiple locations of a sample to create a sparsesampling of the object. A second optical system collects the pluralityof beamlets reflected from the sample and a third optical systemprojects the reference arm onto a reflecting surface and collects aplurality of reflected beamlets. The reflected light from the sample armand reference arms are recombined create optical interference anprojected to an optical image mapper. The optical image mapper isconfigured to spatially separate the beamlets. A spectrometer disperseseach of the interferograms into its respective spectral components andprojects the spectral components of each interferogram in parallel to afocal plane photodetector. The photodetector provides parallelquantification of the photons from the spectral components of each theinterferograms.

A computer module performs inverse transforms on said photonquantifications and quantifies the intensities at each sample depth. Asecond computer module interprets the intensities and provides anaggregate response of the sample which can then be output as a visualdisplay.

In certain alternative embodiments, a light source or multiple lightsources are directed into an interferometric system where light is splitand recombined to form interference fringes. Incident light is dividedinto a sample and reference path by use of a beam splitter. Light fromthe source or sources pass through a beam splitter and is split intoreference and sample arms. Light in the sample arm is converted intobeamlets which are focused on the sample. Beamlets are reflected by thesample and return along the same path of incidence. As light from thesample arm passes through the beam splitter it is directed to an imagemapper. Light in the reference arm is reflected by a mirror and directedtoward the image mapper. Light from the reference and sample arerecombined in the path containing the image mapper in order to formoptical interference. The image mapper receives the recombined lightfrom the sample arm and reference arm as a rectilinear grid and convertsthe rectilinear grid into a linear array allowing for the spectrum ofeach beamlet to be sampled in a direction substantially perpendicular tothe dimension of the linear array.

According to certain embodiments, the apparatus can be configured toimage various sample tissues. In certain implementation, the snapshotapparatus is configured to image the retina. In further implementations,the apparatus is configured to image the cornea. In still furtherimplementations, the apparatus is configured to image ocular epithelium,nervous tissue, or endothelium. One skilled in the art will appreciatethat the apparatus can be configured for imaging other tissue types.

Turning now to the figures, FIG. 1 shows a schematic diagram of thegeometry of the apparatus 101 according to certain embodiments. An arrayof broadband low-coherence light sources 102 provide a plurality ofbeamlets 103. The broadband low-coherence light source can be lightemitting diodes (LEDs), superluminescent diodes (SLD), or Ti:Saph laser.Other light sources are possible. In certain exemplary implementations,an array of point sources is created by using multiple light sourcesarranged in a grid. In certain alternative embodiments, a single lightsource can be converted into multiple point sources by the use of alenslet array, multifaceted reflector, or other optics capable ofconverting a single source into multiple point sources. According tocertain implementations, gradient-index optics are used. These multiplesources enable/create multiple beamlets for sparse sampling of thesample.

Prior art scanning OCT systems have typically sampled using grids ofapproximately 100×500 μm generating thousands of samples over an areaof, for example, 6×6 mm. In contrast, according to certain embodiments,a single snapshot may comprise only hundreds of individual point samplesover a grid of, for example 2000×2000 μm over a larger area of sample,for example 10×10 mm. One skilled in the art will appreciate that arange sparse sampling grids are possible.

The beamlets are projected to a beam splitter 109 which splits the beamsinto a reference arm 113 and a sample arm 111, with each arm comprisingof a plurality of beamlets. The sample arm 111 is projected to a sampleobjective 117 which projects the sample arm 111, in focus and in phase,onto multiple locations of a sample to be imaged 119. Because thebeamlets cover a wide area of the sample in a single “snapshot”, theneed to scan the sample along the XY plane is eliminated as are thegalvanic mirrors and other moving parts that are required for suchscanning. The size of the beamlet array can be adjusted to cover anydesired field by changing the collimation/relay or projection opticsresponsible for delivering the beamlets to the sample. Sampling densitycan be changed by increasing the number of sources or increasing thenumber of facets, lenslets, or other structures responsible forgenerating multiple beamlets.

According to certain alternative embodiments, the disclosed apparatus isa hybrid of conventional scanning OCT and snapshot OCT. According tothese embodiments, multiple snapshots (each with sparse sampling of thesample) are taken sequentially. The sequential snapshots are integratedto yield an image with greater spatial field of view or increasing thesampling density. This has the effect of yielding an image spatialresolution similar to that of a scanning OCT system but at reduced costand complexity of the galvanic scanning mirrors.

Light reflected from the multiple locations on the sample 119 iscollected into parallel beamlets by an objective 117 and projected backto the beam splitter 109. Light from the reference arm 113 is reflectedfrom the reference mirror 114 and back to the beam splitter where it isrecombined with light reflected by the sample 119 to generate aplurality of interferograms from the interference between the sample armbeamlets and the reference arm beamlets. The plurality of interferogramsare projected onto an image mapper system 121. Light enters the imagemapper system 121 as a square array which the image mapper system 121converts into a linear array and projects on to a spectrometer 123.Within the spectrometer 123, the interferograms are dispersed into theirspectral components 127. The spectral components of each of theinterferograms are detected along the focal plane array 131. The focalplane array 131 detects and quantifies the photons of each interferogramin parallel, thus preserving the spatial relationship from the sample119.

FIG. 2A shows a schematic diagram of an alternative embodiment whereinrather than providing beamlets from an array of low-coherence lightsources, a single low coherence light source is used and beamlets areproduced after the beam has been split. According to these embodiments,a broadband low-coherence light source 203 projects low-coherence lightto a beam splitter 109 that splits the beam into a sample arm 211 and areference arm 213. According to certain embodiments, the light from thelow coherence light source 203 is first project through a firstobjective 205 and an aperture array 207 before being projected to thebeam splitter 109.

In certain embodiments, the sample beam 211 is then split by a lensletarray 215 into a plurality of sample beamlets that are projected throughan objective 217 onto the sample to be imaged 119. Other means ofgenerating sample beamlets are possible. The sample beamlets areprojected onto the multiple locations within the sample 119, in focusand in phase. The beamlets are reflected by the sample 119 and collectedin parallel by the objective 217. A reference objective projects thereference arm 213 to a reference mirror 214 and collects the reflectedbeam. According to certain embodiments, light reflected from thereference mirror 214 is projected to a dispersion compensation element225. Light reflected from the sample 219 and the reference mirror 214are recombined at the beam splitter 109 to produce a plurality ofinterferograms which are projected to an image mapper system 121 as asquare array. The image mapper system 121 coverts the square array intoa linear array and spatially separates the plurality of interferograms.The plurality of interferograms are then projected to a spectrometer 123which disperses each interferogram into each of its spectral componentsand projects the spectral components onto a photo-detector (not shown).

In an alternative embodiment, best shown in FIG. 2B, the snapshotapparatus is integrated with a fundus camera 227 for imaging the retinaltissues. The parallel OCT device creates an array of sampling points andthe fundus integration system projects the array of sampling points ontothe ocular tissues to achieve sparse sampling of the eye 219. In certainimplementations, sparse sampling of the eye is achieved by use of anobjective lens 217 where the beamlets used for sampling the retina areplaced at the front focus of the objective 217. The eye 219 is locatedat the back focus of the objective such that the beamlets are collimatedand directed thru the pupil 223 of the eye 219. The optics of the eyefocus the beamlets on the retina at multiple field points. The multiplesampled beamlets are reflected or scattered by the retina back along theoriginal path of incidence. Beamlets used to sample the retina are thenrecombined with the light reflected from the reference mirror 214 toform interference fringes 229 which are projected to the image mapper121.

FIG. 3 A shows a schematic diagram of the image mapper system 121according to certain embodiments. The image mapper system 121 spatiallyseparates the beamlets from the reference and sample arm according totheir point of reflection from the reference mirror and samplerespectively. The light entering image mapper system 121 enters as asquare or rectilinear array 303 and must be converted to a linear array305. One skilled in the art will appreciate that multiple approaches canbe used to affect this conversion. According to certain embodiments,best shown in FIG. 3B, the square array 303 is converted to a lineararray 305 using fiber optics 305. In such an embodiment, the imagemapper system uses a plurality of optical fibers 307, with fiber eachhaving collecting end 309 end and transmitting end 311. The collectingend 309 is positioned to receive scattered light in a non-linear arrayfrom the reference and sample arms. The transmitting ends 311 arepositioned in a linear array 305 such that the transmitted light can bedetected and quantified by the photodetector.

In alternative embodiments, best shown in FIG. 3C, a prism array isused. Two configurations are shown. A first configuration 313 separatesspatial information in the XZ plane. A second configuration 315separates spatial information in the YZ plane. The prism array is amultifaceted array of prisms where each prism has a specific set of tiltangles for converting a rectilinear grid of beamlets into a linear arrayof beams. Other configurations are possible as will be appreciated byone skilled in the art.

FIGS. 4A-B are schematics showing an optical spectrometer according tocertain embodiments in which an array of point objects from the imagemapper 402 is imaged onto a two dimensional detector array 404. Agrating prism 406 or other dispersive device separates the spectralcontent (wavelength information) along the direction substantiallyperpendicular to the array of point sources 402. In FIG. 4A a lineararray of points is imaged onto a CCD 404. This is shown in the xz plane.In FIG. 4B the same device is dispersing the spectrum along a directionsubstantially perpendicular to the input array 402. The spectralinformation for each point is projected in the yz plane. Thisarrangement allows the spectral information of each point to be gatheredsimultaneously on a two dimensional detector array 404 without scanning.

In certain implementations, best shown in FIG. 5, the spectrometer'sdispersive device is a prism 505. In this implementation, light from theimage mapper 502 is projected to prism 505 and dispersed into itsspectral components 507. In further implementations, best shown in FIG.6, the spectrometer's dispersive device is a diffraction grating 605. Inthis implementation, light from the image mapper 602 is projected toprism 605 and dispersed into its spectral components 607. As will beappreciated by those skilled in the art, other dispersive devices arepossible, such as holographic gratings.

FIG. 7 shows a representative view of data collected from the focaldetector plane according to certain embodiments. Each spectrum 709represents the interferogram from a single beamlet/point in the object.The x-axis is distance from center of the interferogram in millimetersalong the X-axis. Y-axis represents wavelength information of thespectrum and encodes depth in the sample.

FIG. 8 is a schematic model of an exemplary embodiment of the imagemapper optics 121. Beamlets enter a first faceted prism array 802 as arectilinear array 804. The first faceted prism array 802 convert therectilinear array 804 into a linear array 806 and prism angles deflectthe linear array toward a second faceted prism array 812. The secondfaceted prism array 812 makes all beams coplanar. The second facetedprism array 812 has prism angles that deflect beamlets such that allbeamlets are passed to spectrometer.

FIG. 9 is a schematic representation of the image mapper 121 andspectrometer 123 according to certain embodiments. Light from the sample911 and the reference mirror 913 is recombined at the beam splitter 109and projected to the image mapper 121. The image mapper 121 spatiallyseparates the beamlets and converts them into a linear array. Beamletsenter a first faceted prism array 802 as a rectilinear array 804. Thefirst faceted prism array 802 convert the rectilinear array 804 into alinear array 806 and prism angles deflect the linear array toward asecond faceted prism array 812. The second faceted prism array 812 makesall beams coplanar. The second faceted prism array 812 has prism anglesthat deflect beamlets such that all beamlets are passed to spectrometer.In an exemplary embodiment, the spectrometer is comprised of a relaylens and a diffraction grating 903 which decompose the interferogramsinto their spectral components 907. The spectral components 907 of eachinterferogram are projected onto the focal plane array 131 whichquantifies the photons. In some embodiments, the photodetector is acomplementary metal oxide semiconductor (CMOS) area sensor. In stillother embodiments the photodetector is a charge-coupled device (CCD).

FIG. 10 is a block diagram of the image processing process 1001according to certain embodiments. Data from the photodetector 803 issent to a first computer module 1005. The first module 1005 performs aninverse transformation 1007 of the photon quantities for eachinterferogram to generate an image showing the intensity of theinterference at each depth in the tissue for each beam. A secondcomputer module 1011 receives input from the first computer module 1005and receives said quantifications of depth intensities 1009. The secondcomputer module 1011 aggregates depth intensity information 1013 foreach beamlet interferogram and assembles a composite image of the samplebeing imaged. The aggregation of depth intensity information 1013 isthen sent to a visual display 1015 for evaluation by the user.

In certain embodiments, the aggregates depth intensity information isused to quantify retinal nerve thinning. In further embodiments, theaggregate depth intensity information is used to quantify retinalthickening.

According to certain embodiments, as best shown in FIG. 11, provided isa method of imaging an eye that comprises providing a plurality of lowcoherence beamlets 1101, splitting the plurality of beamlets into areference arm directed to a reflecting surface and a sample arm directedto multiple locations of an eye 1103, recombining beamlets reflectedfrom the reflecting surface and beamlets reflected from the eyegenerating a plurality of interferograms 1105, converting the pluralityof beamlets to a linear array of beamlets 1107; dispersing each of theplurality of beamlets into its spectral components 1109, performing inparallel photon quantification of each of the plurality of beamlets1111.

According to certain alternative embodiments, provided is a method ofimaging an eye that comprises providing light from a low coherence lightsource and splitting the light with a beam splitter into a reference armand a sample arm. The method further comprises splitting the sample arminto a plurality of beamlets and directing the plurality of beamlets tothe region of the eye to be imaged; transmitting the reference arm to areflecting surface; recombining light reflected from the eye and thereflecting surface generating a plurality of interferograms; convertingthe plurality of beamlets to a linear array of beamlets; dispersing eachof the plurality of beamlets into its spectral components; performing inparallel photon quantification of each of the plurality of beamlets.

In certain aspects, the method further comprising performing inversetransforms on the photon quantifications and quantifying the intensitiesat each depth of the eye 1113. In further aspects, the method furthercomprises interpreting the intensities and providing an aggregateresponse of the ocular tissues 1115. In still further aspects, thedisclosed method further comprises calculating retinal thickening basedon the aggregate response of ocular tissues 1117. In still furtheraspects, the method further comprises calculating nerve fiber layerthinning.

FIG. 12 is a block diagram illustrating an exemplary operatingenvironment for performing the disclosed method. This exemplaryoperating environment is only an example of an operating environment andis not intended to suggest any limitation as to the scope of use orfunctionality of operating environment architecture. Neither should theoperating environment be interpreted as having any dependency orrequirement relating to any one or combination of components illustratedin the exemplary operating environment.

The present methods and systems can be operational with numerous othergeneral purpose or special purpose computing system environments orconfigurations. Examples of well known computing systems, environments,and/or configurations that can be suitable for use with the system andmethod comprise, but are not limited to, personal computers, servercomputers, laptop devices, and multiprocessor systems. Additionalexamples comprise set top boxes, programmable consumer electronics,network PCs, minicomputers, mainframe computers, distributed computingenvironments that comprise any of the above systems or devices, and thelike.

The processing of the disclosed methods and systems can be performed bysoftware components. The disclosed system and method can be described inthe general context of computer-executable instructions, such as programmodules, being executed by one or more computers or other devices.Generally, program modules comprise computer code, routines, programs,objects, components, data structures, etc. that perform particular tasksor implement particular abstract data types. The disclosed method canalso be practiced in grid-based and distributed computing environmentswhere tasks are performed by remote processing devices that are linkedthrough a communications network. In a distributed computingenvironment, program modules can be located in both local and remotecomputer storage media including memory storage devices.

Further, one skilled in the art will appreciate that the systems andmethods disclosed herein can be implemented via a computing device inthe form of a computer 1201. The components of the computer 1201 cancomprise, but are not limited to, one or more processors or processingunits 1203, a system memory 1212, and a system bus 1213 that couplesvarious system components including the processor 1203 to the systemmemory 1212. In the case of multiple processing units 1203, the systemcan utilize parallel computing.

The system bus 1213 represents one or more of several possible types ofbus structures, including a memory bus or memory controller, aperipheral bus, an accelerated graphics port, and a processor or localbus using any of a variety of bus architectures. By way of example, sucharchitectures can comprise an Industry Standard Architecture (ISA) bus,a Micro Channel Architecture (MCA) bus, an Enhanced ISA (EISA) bus, aVideo Electronics Standards Association (VESA) local bus, an AcceleratedGraphics Port (AGP) bus, and a Peripheral Component Interconnects (PCI),a PCI-Express bus, a Personal Computer Memory Card Industry Association(PCMCIA), Universal Serial Bus (USB) and the like. The bus 1213, and allbuses specified in this description can also be implemented over a wiredor wireless network connection and each of the subsystems, including theprocessor 1203, a mass storage device 12012, an operating system 1205,imaging software 1206, imaging data 1207, a network adapter 1208, systemmemory 1212, an Input/Output Interface 1210, a display adapter 1209, adisplay device 1211, and a human machine interface 1202, can becontained within one or more remote computing devices 1214 a,b,c atphysically separate locations, connected through buses of this form, ineffect implementing a fully distributed system.

The computer 1201 typically comprises a variety of computer readablemedia. Exemplary readable media can be any available media that isaccessible by the computer 1201 and comprises, for example and not meantto be limiting, both volatile and non-volatile media, removable andnon-removable media. The system memory 1212 comprises computer readablemedia in the form of volatile memory, such as random access memory(RAM), and/or non-volatile memory, such as read only memory (ROM). Thesystem memory 1212 typically contains data such as imaging data 1207and/or program modules such as operating system 1205 and imagingsoftware 1206 that are immediately accessible to and/or are presentlyoperated on by the processing unit 1203.

In another aspect, the computer 1201 can also comprise otherremovable/non-removable, volatile/non-volatile computer storage media.By way of example, FIG. 12 illustrates a mass storage device 12012 whichcan provide non-volatile storage of computer code, computer readableinstructions, data structures, program modules, and other data for thecomputer 1201. For example and not meant to be limiting, a mass storagedevice 12012 can be a hard disk, a removable magnetic disk, a removableoptical disk, magnetic cassettes or other magnetic storage devices,flash memory cards, CD-ROM, digital versatile disks (DVD) or otheroptical storage, random access memories (RAM), read only memories (ROM),electrically erasable programmable read-only memory (EEPROM), and thelike.

Optionally, any number of program modules can be stored on the massstorage device 12012, including by way of example, an operating system1205 and imaging software 1206. Each of the operating system 1205 andimaging software 1206 (or some combination thereof) can compriseelements of the programming and the imaging software 1206. Imaging data1207 can also be stored on the mass storage device 12012. Imaging data1207 can be stored in any of one or more databases known in the art.Examples of such databases comprise, DB2®, Microsoft® Access, Microsoft®SQL Server, Oracle®, mySQL, PostgreSQL, and the like. The databases canbe centralized or distributed across multiple systems.

In another aspect, the user can enter commands and information into thecomputer 1201 via an input device (not shown). Examples of such inputdevices comprise, but are not limited to, a keyboard, pointing device(e.g., a “mouse”), a microphone, a joystick, a scanner, tactile inputdevices such as gloves, and other body coverings, and the like These andother input devices can be connected to the processing unit 1203 via ahuman machine interface 1202 that is coupled to the system bus 1213, butcan be connected by other interface and bus structures, such as aparallel port, game port, an IEEE 13912 Port (also known as a Firewireport), a serial port, or a universal serial bus (USB).

In yet another aspect, a display device 1211 can also be connected tothe system bus 1213 via an interface, such as a display adapter 1209. Itis contemplated that the computer 1201 can have more than one displayadapter 1209 and the computer 1201 can have more than one display device1211. For example, a display device can be a monitor, an LCD (LiquidCrystal Display), or a projector. In addition to the display device1211, other output peripheral devices can comprise components such asspeakers (not shown) and a printer (not shown) which can be connected tothe computer 1201 via Input/Output Interface 1210. Any step and/orresult of the methods can be output in any form to an output device.Such output can be any form of visual representation, including, but notlimited to, textual, graphical, animation, audio, tactile, and the like.In an aspect, the snapshot OCT apparatus 101 can be coupled to computer1201 via Input/Output Interface 1210. For example, snapshot OCTapparatus 100 can transfer images captured to the computer 1201 foranalysis and storage.

The computer 1201 can operate in a networked environment using logicalconnections to one or more remote computing devices 1214 a,b,c. By wayof example, a remote computing device can be a personal computer,portable computer, a server, a router, a network computer, a peer deviceor other common network node, and so on. Logical connections between thecomputer 1201 and a remote computing device 1214 a,b,c can be made via alocal area network (LAN) and a general wide area network (WAN). Suchnetwork connections can be through a network adapter 1208. A networkadapter 1208 can be implemented in both wired and wireless environments.Such networking environments are conventional and commonplace inoffices, enterprise-wide computer networks, intranets, and the Internet1215.

For purposes of illustration, application programs and other executableprogram components such as the operating system 1205 are illustratedherein as discrete blocks, although it is recognized that such programsand components reside at various times in different storage componentsof the computing device 1201, and are executed by the data processor(s)of the computer. An implementation of imaging software 1206 can bestored on or transmitted across some form of computer readable media.Any of the disclosed methods can be performed by computer readableinstructions embodied on computer readable media. Computer readablemedia can be any available media that can be accessed by a computer. Byway of example and not meant to be limiting, computer readable media cancomprise “computer storage media” and “communications media.” “Computerstorage media” comprise volatile and non-volatile, removable andnon-removable media implemented in any method or technology for storageof information such as computer readable instructions, data structures,program modules, or other data. Exemplary computer storage mediacomprises, but is not limited to, RAM, ROM, EEPROM, flash memory orother memory technology, CD-ROM, digital versatile disks (DVD) or otheroptical storage, magnetic cassettes, magnetic tape, magnetic diskstorage or other magnetic storage devices, or any other medium which canbe used to store the desired information and which can be accessed by acomputer.

In an aspect, provided is a snapshot spectral domain optical coherencetomographer comprising: a light source providing a plurality ofbeamlets; a beam splitter, splitting the plurality of beamlets into areference arm and a sample arm; a first optical system that projects thesample arm onto multiple locations of a sample; a second optical systemfor collection of a plurality of reflected sample beamlets; a thirdoptical system projecting the reference arm to a reflecting surface andreceiving a plurality of reflected reference beamlets; a parallelinterferometer that provides a plurality of interferograms from each ofthe plurality of sample beamlets with each of the plurality of referencebeamlets; an optical image mapper configured to spatially separate theplurality of interferograms; a spectrometer configured to disperse eachof the interferograms into its respective spectral components andproject the spectral components of each interferogram in parallel; and aphotodetector configured to receive the spectral components of eachinterferogram and provide in parallel photon quantification.

In certain aspects, the light source is a an array of broadbandlow-coherence light sources. In further aspects, the light source is asingle broadband low-coherence light source split into a plurality ofbeamlets by a lenslet array.

In an aspect, the optical image mapper converts the beamlets into alinear array of beamlets.

In further aspects, the spectrometer further comprises a diffractiongrating. In still further aspects, the spectrometer further comprises aprism.

In an aspect, the sample arm beamlets are projected to the sample infocus and in phase.

In certain aspects, the photodetector is a CMOS sensor. In furtheraspects, the photodetector is a CCD sensor.

In an aspect, the first and second optical systems are a fundus camera.In further aspects, the first and second optical systems are an anteriorsegment camera or a cornea camera.

In an aspect, the apparatus further comprises: a computer module whereinsaid computer module performs inverse transforms on the photonquantifications and quantifies intensities at each depth. In certainaspects, the apparatus further comprises a second computer module thatinterprets the intensities and provides an aggregate response of theobject. In still further aspects, the aggregate response from the secondcomputer module quantifies nerve fiber layer thinning. In certainaspects the aggregate response from the second computer modulequantifies the amount of retinal thickening.

In certain aspects, the sample is a biological tissue. In furtheraspects, the biological tissue is selected from a group consisting ofretina, cornea, epithelium, nervous tissue, or endothelium.

In certain aspects, provided is method of imaging an eye comprising:providing a plurality of low coherence beamlets; transmitting theplurality of low coherence beamlets to a beam splitter, wherein the beamsplitter splits the plurality of beamlets into a reference arm directedto a reflecting surface and a sample arm directed to multiple locationsof an eye; recombining beamlets reflected from the reflecting surfaceand beamlets reflected from the eye generating a plurality ofinterferograms; converting the plurality of beamlets to a linear arrayof beamlets; dispersing each of the plurality of beamlets into itsspectral components; and performing in parallel photon quantification ofeach of the plurality of beamlets.

In an aspect, the method further comprises performing inverse transformson the photon quantifications and quantifying the intensities at eachdepth of the eye. In certain aspects, the method further comprisesinterpreting the intensities and providing an aggregate response of theeye. In still further aspects, the method further comprises calculatingretinal thickening. In yet further aspects, the method further comprisescalculating nerve fiber layer thinning.

In an aspect, provided is a snapshot spectral domain optical coherencetomographer comprising: a housing and a system of optical componentsdisposed in the housing capable of parallel optical coherence imaging ofa sample; a broadband low coherence light source providing light to abeam splitter wherein the beam splitter splits the light into areference arm and a sample arm; a first optical element converting thesample arm into a plurality of beamlets and focusing the plurality ofbeamlets on the sample; a reflecting surface reflecting light from thereference arm, wherein the light reflected from the reflecting surfaceis recombined with the plurality of beamlets reflected from the sampleproducing a plurality of beamlet interferograms; an optical image mapperconfigured to receive and spatially separate the plurality of beamletinterferograms; a spectrometer configured to disperse each of thebeamlet interferograms into its respective spectral components andproject the spectral components of each interferogram in parallel; aphotodetector configured to receive the spectral components of eachbeamlet interferogram and provide in parallel photon quantification; anda computer module wherein said computer module performs inversetransforms on the photon quantifications and quantifies intensities ateach depth.

Various modifications to the implementations described in thisdisclosure may be readily apparent to those skilled in the art, and thegeneric principles defined herein may be applied to otherimplementations without departing from the spirit or scope of thisdisclosure. Thus, nothing in this specification is intended to implythat any feature, characteristic, or attribute of the disclosed systemsand processes is essential.

Certain features that are described in this specification in the contextof separate implementations also can be implemented in combination in asingle implementation. Conversely, various features that are describedin the context of a single implementation also can be implemented inmultiple implementations separately or in any suitable subcombination.Moreover, although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. In certain circumstances, multitasking and parallel processingmay be advantageous. Moreover, the separation of various systemcomponents in the implementations described above should not beunderstood as requiring such separation in all implementations, and itshould be understood that the described apparatus components and systemscan generally be integrated together.

What is claimed is:
 1. A snapshot spectral domain optical coherencetomographer comprising: a. a light source; b. an optical systemconfigured receive light from a light source and to project a pluralityof beamlets onto multiple locations of a sample and to generate aplurality of beamlet interferograms by recombining the plurality ofbeamlets reflected from the sample with a plurality of referencebeamlets reflected from a reference surface; d. an optical image mapperconfigured to spatially separate the beamlets; e. a spectrometerconfigured to disperse each of the interferograms into its respectivespectral components and project the spectral components of eachinterferogram in parallel; and f. a photodetector configured to receivethe spectral components of each interferogram and provide in parallelphoton quantification.
 2. The apparatus of claim 1, wherein the lightsource is an array of broadband low-coherence light sources.
 3. Theapparatus of claim 1, wherein the light source is a single broadbandlow-coherence light source split into a plurality of beamlets by alenslet array.
 4. The apparatus of claim 1, wherein the optical imagemapper converts the beamlets into a linear array of beamlets.
 5. Theapparatus of claim 1 wherein the spectrometer further comprises adiffraction grating.
 6. The apparatus of claim 1 wherein thespectrometer further comprises a prism.
 7. The apparatus of claim 1wherein the sample arm beamlets are projected to the sample in focus andin phase.
 8. The apparatus of claim 1 wherein the optical systemsfurther comprises a fundus camera.
 9. The apparatus of claim 1 whereinthe optical system further comprises an anterior segment camera.
 10. Theapparatus of claim 1 further comprising: a computer module wherein saidcomputer module performs inverse transforms on the photonquantifications and quantifies intensities at each depth.
 11. Theapparatus of claim 10 further comprising: a second computer module thatinterprets the intensities and provides an aggregate response of theobject.
 12. The apparatus of claim 11 wherein the aggregate responsefrom the second computer module quantifies nerve fiber layer thinning.13. The apparatus of claim 11 wherein the aggregate response from thesecond computer module quantifies the amount of retinal thickening. 14.The apparatus of claim 1 wherein the sample is selected from a groupconsisting of retina, cornea, epithelium, nervous tissue, orendothelium.
 15. A method of imaging an eye comprising: a. providing aplurality of low coherence beamlets; b. transmitting the plurality oflow coherence beamlets to a reflecting surface and to multiple locationsof an eye; c. recombining beamlets reflected from the reflecting surfaceand beamlets reflected from the eye generating a plurality ofinterferograms; d. converting the plurality of beamlets to a lineararray of beamlets; e. dispersing each of the plurality of beamlets intoits spectral components; f. performing in parallel photon quantificationof each of the plurality of beamlets.
 16. The method of claim 15 furthercomprising performing inverse transforms on the photon quantificationsand quantifying the intensities at each depth of the eye.
 17. The methodof claim 15 further comprising interpreting the intensities andproviding an aggregate response of the eye.
 18. The method of claim 15further comprising calculating retinal thickening.
 19. The method ofclaim 15 further comprising calculating nerve fiber layer thinning.